Adaption of bacteria to hydrostatic and osmotic pressure: a tale of two sisters
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Date
27/06/2011Item status
Restricted AccessEmbargo end date
31/12/2100Author
Black, Stuart Lucas
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Abstract
Adaption to environmental stresses is vital for the survival of all organisms
living in any environment. Two of the major environmental factors in the
deep sea environment are high hydrostatic pressure and high salt concentration.
Hydrostatic pressure and osmotic pressure share similarities in their effects on
organisms living in the deep sea but this overlap has been little explored.
Major studies from Japan and California over the last 40 years have shown the
effects of hydrostatic pressure on bacteria from the deep sea (see [1] for a review).
These are complemented by work by Yancey et al. [2] showing that specific solutes
accumulated in response to osmotic pressure in fish have the ability to enhance
resistance to hydrostatic pressure. However, this work has been done in vitro or
with larger organisms and not much is known about the overlap of osmotic and
hydrostatic pressure in bacteria.
In this study I investigated the effects of osmotic and hydrostatic pressure on
two model organisms: Photobacterium profundum and Escherichia coli. In order
to accomplish this task I developed novel imaging equipment which allows for
high resolution imaging of bacteria at pressure. I also developed a new method of
growing bacteria in 96-well plates at high pressure, which lead to the identification
of a hierarchy of genes essential for the growth of E. coli at pressure. I used the
same 96-well plate technique to monitor the growth of P. profundum at differing
osmotic and hydrostatic pressures. Furthermore I also attempted to analyse the
solutes accumulated by different strains of P. profundum in response to osmotic
and hydrostatic pressures.